package top.lethelh.pattern.interpreter;

/**
 * 解释器模式测试类
 */
public class Client {

    public static void main(String[] args) {
        // 创建环境对象
        Context context = new Context();

        // 创建多个变量对象
        Variable a = new Variable("a");
        Variable b = new Variable("b");
        Variable c = new Variable("c");
        Variable d = new Variable("d");

        // 将变量存储到环境对象中
        context.assign(a, 1);
        context.assign(b, 2);
        context.assign(c, 3);
        context.assign(d, 4);

        // 获取抽象语法树 a - ((b - c) + d)
        AbstractExpression expression = new Minus(a, new Plus(new Minus(b, c), d));

        // 解释(计算)
        int res = expression.interpret(context);
        System.out.println(expression.toString() + " = " + res);
    }
}
